Pectinase is widely distributed in higher plants and microorganisms, and has also been found in some protozoa and insects. In microorganisms, bacteria, actinomycetes, yeasts and molds can metabolize and combine gumase pectinase, which is generally divided into protoprine, pectin hydrolases, pectin lyase (pl) and pectin esterases ( pe ) . Many microorganisms produce protopylases that dissolve pectin, which releases soluble pectin substances from plant tissues.
Application of pectinase in food
1. Pectinase is used for fruit peeling citrus in the sweet orange fruit outer peel is tightly wrapped, often caused by peeling caused a lot of unnecessary embarrassment when eating. Adams and Kirk (1991) reported obtaining whole citrus fruits that were decosted using vacuum osmotic pectinase; Eviott.tinibel et al. (1993) reported a similar study. Lan Hanglian et al. studied the peeling technology of sweet orange whole fruit, and the test showed that the technology consisted of two parts: first, the peel of the fresh fruit was removed by the method of water injection; and then the exposed capsule of the whole fruit was removed by the pectinase treatment method to obtain the peeled whole fruit with bright color, good flavor and rich nutrition.
2. Application of pectinase in fruit juice clarification
Studies on pectinase-clarified fruit juices, dating back to the 1930s, when it was thought that the main cause of cloudiness in fruit and vegetable juices was pectin; Research on the principle of juice clarification began in the 1960s. Yamasaki et al. speculated about a simplified model of pectinase-clarified apple juice, and the essence of pectinase-clarified juice contains two parts: enzymatic hydrolysis and non-enzymatic electrostatic flocculation of pectin. When the pectin in the fruit and vegetable juice is partially hydrolyzed under the action of pectinase, the positively charged protein particles that are wrapped up are exposed, collide with other negatively charged particles, and then aggregate, which leads to the occurrence of flocculation. During the settlement of flocculates, pectinase adsorbs and wraps other suspended particles in the juice, and can be removed by centrifugation and filtration, so as to achieve the purpose of clarification. Chen Jianxuan studied the application of pectinase to clarify sugarcane juice, and found that the pectin substances in sugarcane juice were one of the main triggers for the suspension of colloidal particles in sugarcane juice; The addition of pectinase can specifically hydrolyze pectin substances, so that other colloidal substances in the system are precipitated due to the loss of pectin protection, and the juice is clarified.
3． Oil
In the process of vegetable oil extraction, cell wall degradation enzymes including alkaline pectinase play an important role, such as the addition of alkaline pectinase in olive oil pressing, which can destroy the emulsifying pectin, improve the oil yield, and the expelled oil is very stable when stored, and the content of polyphenols and vitamin e has also increased.
4. In other aspects, the product of pectinase after processing pectin substances can be used as a dietary fiber, which can treat and prevent some chronic diseases. If used rationally, it is expected to develop a new type of health food or medicine to bring good news to patients with chronic diseases.
At present, the research on pectinase mainly focuses on the screening of enzyme-producing strains, the extraction and separation of enzymes, and the improvement of juice juice yield and clarification. Pectinase is widely distributed in nature, but the current application of pectinase is mostly as a single enzyme application,
This makes it difficult for pectinase to be used in the food industry to expand further. Future research on pectinase should be devoted to the study of enzyme regulatory mechanisms at different levels and the mechanism of action of different pectinases on pectin substances. It is believed that with the continuous deepening of pectinase research, pectinase will play a greater role in promoting the development of the food industry.